Multi-station document inserting systems are generally used by organizations such as banks, insurance companies and utility companies for producing a large volume of specific mailings where the contents of each mailpiece are directed to a particular addressee. One of the most important features of the inserting systems is speed, which is measured by the number of mailpieces that can be assembled in a given time period. A modern inserting system is expected to assemble over ten thousand mailpieces per hour. A typical inserter system includes a plurality of serially arranged stations including a sheet feeding station, a folding station and an insertion station. In general, the sheet feeder feeds one or a plurality of sheets of mailing materials to an collator, which collects the fed sheets into a predefined collated packet or stack. Mailing materials are usually printed on a continuous web of paper and the printed paper is cut into individual sheets. These sheets are then collated into individual stacks and each stack is stuffed into an envelope for mailing. One of the conventional ways of sheet collation is to slow down or stop the sheets in an impending collation at a certain point until all the sheets have arrived. This conventional method is cumbersome and inefficient because it requires a drastic change in machine speed.
It is desirable to provide a method and a device for sheet collation wherein the sheets can be kept substantially at the same speed throughout the collation process.